Bit-stock attachment



Cab

ALBERT A.

ascent, or snoer/ions, MASSACHUSETTS.

BIT-STOCK ATTACHMENT.

Application filed December 17, 1924. Serial No. 756,508.

My invention relates to improvements in bit stocks. and it consists .in the combinations, constructions and arrangements herein described and claimed.

rin object otl the invention is to provide a bit stock ot the type having a sleeve turnably inounted on a shank thereol for clainp- .ing the jaws oil the bit stock in closed position with an attachment which can be conveniently and easily adjusted on the shank to and trein position to rictionally engage with the clamping sleeve, and to then tend to hold the clamping sleeve against turning on he shank when the bit stock is in use.

further object ot the invention .is the provision of an attachment of the character described which includes a locking` sleeve adapted to be grasped coincineiitly with the usual clamping sleeve oi the bit stock so that p the operator ot the bit stock can hold the bit stock iirnily and manipulate the bit stock accurately. j

@ther objects and advantages will be apparent trom the following description, con sidcred in conjunction with the accompanying drawings, in which:

.Figure l isa perspective group view showing a bit stock equipped with an attachment embodying the invention, the bit stock shank 0 and the elements which are norinally carried thereby being shown separated, and

Figure 2 is a view partly in side elevation and partly in vertical section, showing the elements which are exhibited in Figure 1 assenibled with the attachment in frictional engagement with the clamping sleeve of the bit stock.

In the drawings, I show abit stock having a handle l, only a portion of which is shown, to which is attached a shank 2. The shank 2 is bifurcated at its tree end by a longitudinally extending slot 3 for the reception ot portions ot' the jaws 4. The shank 2 is pro vided with external screw threads 5 for engaging with the internal screw threads 6 on the inner end portion of a clamping sleeve?. rlhe clamping sleeve 7 has the bore thereof reduced at its outer end as indicated at 8 for engaging with inclined outer faces ot' the jaws l to torce said jaws toward each other, and to position to grip a bit, not shown, when the latter is inserted between the jaws 4c and the clamping sleeve is screwed inwardly on the shank, the jaws normally being urged apart at their outer ends in any suitable known manner, as by means ot a spring such as is partially shown at 9 in Figure 2. The construction described so iar is ordinary and forms no part of the invention except in so lar as it cooperates with the parts which will now be descrioed. ln tua practice, the clamping sleeve T is likely to turn on the shank when the bit stock with a bit gripped between the jaws is used in an ordinary manner to an extent suiiicient to permit release of the bit from the jaws, which et course retards the progress ot the particular work which is being done, and inoreover may cause the loss ot a bit as when the bit is extended downward through an opening in the wall ot a closed chamber or in alike place. Y

lilly invention provides means -or overcoming this tendency ot the clamping sleeve to turn accidentally'on the shank. ing out the invention, the threads 6 are eX- tended on the shank 2 farther than is usual toward the inner end of the shank and the shank is flattened longitudinally at the inn ner end of the slot 3 to provide diainetrically opposite tlat faces on the shank as indicated at j j it locking sleeve ll is provided with a counterbore l2 at the outer end thereof extending for slightly incre than hallnthe lengthof the locking sleeve. The bore ot the locking sleeve has screw threads indicated at 13 for engaging with the screw threads of the shank 2 and the counter-bore l2 is adapted to receive the inner end portion of the clamping sleeve 7. A spacing washer le is slidable on the shank 2 and is enlarged inwardly at 15 to provide Vopposite portions having flat faces for engaging with the flat faces l0 on the shank 2 to prevent rotation of the washer lll on the shank.

From the foregoing description of the various parts of the device, the operation thereot niay be readily understood. rllhe washer 14: is placed on the shank 2 within the counter-bore l2 and between the shoulder i6 at the inner end of the counter-bore l2 and the inner end of the clamping sleeve. The

claniping sleeve. 7 is adjusted on the shank` to position to clamp the jaws 4: in gripping relation to a bit or like tool which has been inserted between the jaws. y sleeve l1 then is turned on the shank toward the clamping sleeve 7 until the spacing washer la has been clamped rinly be* tween the shoulder 16 and the inner end oit the clamping sleeve 'l' in trictional Contact The locking with hoth the clamping sleeve and the locking sleeve. rhe locking sleeve 1l and the Clamping sleeve 7 then are held as a unit in the. one hand of the operator when the hanu dle of the brace is turned bymeans of the other hand oi' the'operator in the usual manner, and Wien Work is being accomplished in the direction which would tend to cause inward movement oi the clamping sleeve 7 on the shanl Where such movement is possible. The locking sleeve ll and the spacing' Washer lll Will `lL'unotion to prevent inward movement ot the sleeve 7 on the shank from the position just described, even though the mig'agement oic the bit which is held between e jaws with s L jaws and the engagement the jaws -with the outer end of the clamping sleeve ivo-nld permit such inward movement. addition, the rictional Contact "0 o1' the u ner lll With the sleeve Z tends to prevent retrograde or out-Ward movement ot the el 7 on the shank, and thus rnping; sleeve practice is eilective to prevent aceinem/il loosening of the grip otthc-zl jaws or he bit or lilte tool which has been held beth jaws, lvioreover, the clamping and the locking sleeve ll can be 1 ed :s a unit, thus atl'ording an ample hold when it is desired to manipulate sIianlr oi' the brace by turning` it anc` a kool, such as sorerv driver bit which is held between the jaivs about the axis ot the shank and tool, as in turning)` a small screw or a ill ot small size, and particularly when starting a small screw in the object to which it is to be secured. The outer end Leidt/seV portion of the clamping sleeve ordinarily is lnurled or roughened as indicated at 17 and the locking sleeve ll is knurled or roughened as indicated at 1.8 so that the clamping sleeve and locking sleeve can be firmly grasped and held against slipping in the hand oi an 0perator.

bviously7 the invention is susceptible or embodiment in Jjorms other than that which has been illustrated in the acoompanyiiniI draw las and l therefore consider as my own all such modifications and adaptations thereof as irly all Within the scope of the appended claim.

ri'he combination with a bit stool; havingl :i shank and a sleeve turnable on the shank, to and from position to hold the jaws of the hit steelt closed, iid shank having a longitidinally extending fiat tace at the inner Vend of said clamping sleeve, of a Washer slidable on the shank at the inner end ot' the Ciampinosleeve, said Washer having` an inwardly extending stop portion in sliding Contact with said fiat face of the shank tor holding the Washer against rotation on the shank, and a locking` sleeve in threaded enlganement With the shank 'for moving said washer longitudinally of the shank to and from position to irictionally engage with the inner end of the said clamping sleeve, said locking sleeve having a eounterbore at its outer end for the reception of said Washer and the inner end port-ion of said clamping; sleeve.

ALBERT A. JACUB. 

